JP2004356802A - Data processing method and data processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data processing method and a data processing apparatus for verifying forgery with high accuracy even when verification object data are subjected to magnification / reduction processing by managing electronic signature data without embedding the data to the verification object data. <P>SOLUTION: According to a configuration 100a at a signature generation side, electronic signature data at the signature generation side are generated and image correction information is generated, and an electronic signature management table 103a including an image ID, the electronic signature data, and the image correction information is stored. According to a configuration 100b at a signature verification side, the image correction information and the electronic signature data at the signature generation side corresponding to a data ID are acquired from the electronic signature management table 103a, the verification object data are corrected by using the acquired image correction information, electronic signature data at the signature verification side are generated on the basis of the verification object data, the electronic signature data at the signature generation side are compared with the electronic signature data at the signature verification side, and the presence / no presence of the forgery is discriminated on the basis of a result of comparison. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a data processing method and a data processing apparatus for generating electronic signature data from image data or the like by using a configuration on a signature generation side and detecting whether the image data or the like has been tampered with the electronic signature data using a configuration on a signature verification side. It is about.
[0002]
[Prior art]
As a method for detecting falsification of image data, there is a method of embedding digital signature data in image data using digital watermark technology. For example, when a fragile digital watermark is embedded in a bitmap image, a hash value is calculated from a bit-plane other than the LSB (least significant bit) as shown in FIG. There is a method in which a hash value encrypted by an encryption method is embedded in an LSB as digital signature data. When verifying the digital signature data, as shown in FIG. 17, the hash value generated at the time of embedding the digital watermark is decrypted and extracted from the LSB portion of the image data in which the digital signature data is embedded. , A hash value is calculated by the same algorithm as the embedding side, and if both hash values match, it is determined that the image data has not been tampered with (for example, see Non-Patent Document 1 and Patent Document 1). Fragile digital watermarking is suitable for applications that strictly guarantee the originality, but does not allow changing the resolution of image data or irreversible compression.
[0003]
Further, in semi-fragile (semi-fragile) digital watermarking, (i) digital signature data is generated so as to be invariable to some extent even if an image is irreversibly compressed, and (ii) the digital signature data is slightly more MSB than LSB. (Most significant bit) By embedding in the part closer to (most significant bit) and (iii) giving a width to the image estimated from the digital signature data, it is prohibited to change and use the contents of the image data itself, Changes by lossless compression are allowed.
[0004]
[Non-patent document 1]
Koko Matsui, "Basics of Digital Watermarking" (Morikita Publishing Co., Ltd.), pp. 38-48
[Patent Document 1]
JP 2001-42768 A (FIGS. 1 to 4)
[0005]
[Problems to be solved by the invention]
However, if the image size is changed in the above-described conventional falsification detection method, the embedded digital signature data cannot be correctly extracted, and the original image data of the resized image data cannot be obtained. Performing signature verification (ie, comparing digital signature data embedded in image data to be verified with digital signature data generated from the image data to be verified using the same algorithm as the signature generation side) Could not. In other words, in the above-described conventional tampering detection method, the image size (width and height in pixel units) on the signature generation side and the image size on the signature verification side must be the same, and the image size is changed. In such a case, even if the data has not been tampered with, the result of the verification is “tampered”, and there has been a problem that tampering cannot be verified correctly.
[0006]
Therefore, the present invention has been made to solve the above-described problems of the related art, and an object of the present invention is to manage digital signature data without embedding it in data to be verified and to acquire data correction information. Accordingly, it is an object of the present invention to provide a data processing method and a data processing device capable of verifying tampering with high accuracy even if the data to be verified has been subjected to enlargement / reduction processing.
[0007]
[Means for Solving the Problems]
The data processing method executed by the signature generation side configuration according to the present invention includes a step in which the signature generation side configuration receives the input data and a data ID for specifying the input data, and the signature generation side configuration based on the input data. Generating electronic signature data; generating data correction information based on the correction content applied to the input data; data ID specifying the input data; electronic signature data on the signature generation side; And storing an electronic signature management table including at least one combination of data correction information.
[0008]
The data processing method executed by the signature verification-side configuration of the present invention, wherein the signature verification-side configuration receives the data to be verified and a data ID that specifies the data to be verified. Obtaining data correction information corresponding to the data ID specifying the data to be verified and the digital signature data on the signature generation side from the obtained electronic signature management table; and Correcting the data; generating digital signature data on the signature verification side from the corrected data to be verified; comparing the digital signature data on the signature generation side with the digital signature data on the signature verification side; Determining whether the verification target data has been tampered with based on the result.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
<< 1st Embodiment >>
[Configuration of signature generation side]
FIG. 1 is a block diagram illustrating a configuration (data processing device) 100a on the signature generation side that performs a data processing method according to the first embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the signature unit 101.
[0010]
As shown in FIG. 1, the configuration 100a on the signature generation side includes a signature unit 101, an electronic signature management unit 102 on the signature generation side, and a storage unit 103 on the signature generation side. The signature unit 101 calculates and outputs digital signature data and image correction information (data correction information) for image data (input data) input from the input terminal 10. The electronic signature management unit 102 stores information associating the image ID (data ID) input from the input terminal 11 with the electronic signature data and image correction information output from the signature unit 101 as an electronic signature management table 103a. 103.
[0011]
As shown in FIG. 2, the signature unit 101 includes a correction information generation unit 110 and an electronic signature generation unit 111. The electronic signature generation unit 111 generates electronic signature data from the image data input from the input terminal 10 and outputs the generated electronic signature data to the electronic signature management unit 102 via the output terminal 13. The correction information generation unit 110 generates image correction information, and outputs the generated image correction information to the electronic signature management unit 102 via the output terminal 12.
[0012]
The configuration 100a on the signature generation side is, for example, a computer system. The signature unit 101 and the electronic signature management unit 102 are, for example, computing devices of a computer system. The storage unit 103 is, for example, a semiconductor memory or a hard disk device of a computer system. However, the storage unit 103 itself may be a storage device arranged at a different position from the signature unit 101 and the electronic signature management unit 102, for example, a storage device of a server on a network. The information of the electronic signature management table 103a stored in the storage unit 103 is transferred to a signature verification-side configuration 100b described below via, for example, a network.
[0013]
[Configuration of signature verification side]
FIG. 3 is a block diagram showing a configuration (data processing device) 100b on the signature verification side that performs the data processing method according to the first embodiment of the present invention. FIG. 4 is a block diagram showing a configuration of the verification unit 120.
[0014]
As shown in FIG. 3, the signature verification-side configuration 100b transmits the information of the electronic signature management table 103a passed from the verification unit 120, the signature verification-side electronic signature management unit 121, and the signature generation-side configuration 100a. And a storage means 123 on the signature verification side for storing. The verification unit 120 performs a verification process on the image data to be verified (data to be verified) input from the input terminal 21 using the electronic signature data and the image correction information, and outputs a verification result from the output terminal 23. . The electronic signature management unit 121 uses the image ID (ID of the data to be verified) input from the input terminal 31 to output the electronic signature data and the image of the image specified by the image ID from the electronic signature management table 103 a of the storage unit 123. The correction information is extracted and output to the verification unit 120.
[0015]
As shown in FIG. 4, the verification unit 120 includes an image correction unit (data correction unit) 130 and a signature verification unit 131. The image correction unit 130 corrects the image data to be verified input from the input terminal 21 using image correction information obtained from the electronic signature management unit 121 via the input terminal 20. The signature verification unit 131 verifies the image data output from the image correction unit 130 by using the electronic signature data obtained from the electronic signature management unit 121 via the input terminal 22 and outputs the verification result to the output terminal. 23.
[0016]
The configuration 100b on the signature verification side is, for example, a computer system. The verification unit 120 and the electronic signature management unit 121 are, for example, computing devices of a computer system. The storage unit 123 is, for example, a semiconductor memory or a hard disk device of a computer system. However, the storage unit 123 itself on the signature verification side may be a storage device arranged at a different position from the verification unit 120 and the electronic signature management unit 121, for example, a storage device of a server on a network. Further, the storage unit 123 on the signature verification side and the storage unit 103 on the signature generation side can be the same storage device.
[0017]
[Operation of signature generation side]
As shown in FIG. 1, first, image data of an image serving as a target for generating digital signature data is input to the signature unit 101 via the input terminal 10. Further, an image ID (for example, a file name) which is data for specifying an image serving as a target for generating electronic signature data is input to the electronic signature management unit 102 via the input terminal 11.
[0018]
The correction information generation unit 110 shown in FIG. 2 generates image correction information on image data based on the correction content applied to the image data input from the input terminal 10. The image correction information is used at the time of verification to match the image to the same coordinate axes as at the time of signature generation. The image correction information includes, for example, one or more of the following correction data. However, the following correction data is merely an example, and other correction data may be used.
(Correction data i): width and height values of the image
(Correction data ii): Vector data obtained by binarizing the entire image and tracing the contour, and coordinate information of vector intersections
[0019]
For example, in order to enable tampering detection when the image is enlarged / reduced, the image correction information may include the width and height values (correction data i) of the image. Further, in order to enable tampering detection when an operation such as rotation is performed on an image, vector correction data and coordinate information of a vector intersection (correction data ii) may be included as image correction information.
[0020]
The digital signature generation unit 111 shown in FIG. 2 can generate digital signature data by a method similar to a digital signature generation method used for a semi-fragile digital watermark or the like, for example. As shown in FIG. 5A, an orthogonal transform such as DCT (discrete cosine transform) or wavelet (Wavelet) transform is performed on an image for generating a signature, and the image is transformed into DCT coefficients, wavelet coefficients, and the like. . A plurality of arbitrary pairs are selected from the obtained coefficients, and a signature 1 bit is generated for each pair using the following equations (1a) and (1b). The signature length of the entire image is the number of bits equal to the number of pairs.
Sig _i = 0 (p _i -Q _i ≧ 0) (1a)
Sig _i = 1 (p _i -Q _i <0) (1b)
Where p _i And q _i Is a wavelet coefficient in the same subband (subband), and as shown in FIG. _i And q _i Is arranged by the wavelet coefficient p _i And q _i Vector ν corresponding to the difference _i Is determined by Also, Sig _i Is the wavelet coefficient p _i And q _i Is a signature bit indicating the relationship with
[0021]
The electronic signature management unit 102 in FIG. 1 includes image correction information obtained from the correction information generation unit 110 via the output terminal 12, electronic signature data obtained from the electronic signature generation unit 111 via the output terminal 13, An image ID obtained from the input terminal 11 is stored in the storage unit 103 in association with an electronic signature management table 103a. The digital signature management table 103a has a function of storing digital signature data and image correction information associated with an image ID, storing electronic signature data and image correction information corresponding to the image ID, and a function of retrieving them.
[0022]
[Operation of the signature verification side]
As shown in FIG. 3, the image data of the target image to be verified is input to the input terminal 21 and the image ID of the target image is input to the input terminal 31. The electronic signature management unit 121 extracts electronic signature data and image correction information corresponding to the image ID input from the input terminal 31 from the electronic signature management table 103a, and outputs the electronic signature data and the image correction information to the verification unit 120.
[0023]
4 corrects image data obtained from the input terminal 21 using image correction information obtained from the electronic signature management means 121 via the input terminal 22. The image correction information of the electronic signature management table 103a stored in the storage unit 123 includes, for example, one or more of the following correction data. However, the following correction data is merely an example, and other correction data may be used.
(Correction data i): width and height values of the image
(Correction data ii): Vector data obtained by binarizing the entire image and tracing the contour, and coordinate information of vector intersections
[0024]
For example, in order to enable tampering detection when the image is enlarged / reduced, the image correction information may include the width and height values (correction data i) of the image. In this case, an image having the same width and the same height as when digital signature data is generated is generated by using an image complement filter or a thinning filter.
[0025]
Further, in order to enable tampering detection when an operation such as rotation is performed on an image, vector correction data and coordinate information of a vector intersection (correction data ii) may be included as image correction information. When an operation such as rotation is performed on the image, for example, the following steps ST1 to ST3 are performed.
(Step ST1): The input image is binarized, the outline is traced to acquire vector data, and the intersection coordinates of the vector are obtained as feature points.
(Step ST2): The obtained feature points are rotated and enlarged / reduced to obtain a magnification and an angle that best match the original image.
(Step ST3): Based on the obtained magnification and angle, the image is scaled / rotated by affine transformation or the like to obtain an image of the same size as the original image.
[0026]
4 verifies the corrected image data obtained by the image correcting unit 130 using the digital signature data obtained from the signature managing unit 121, and outputs the verification result from the output terminal 23. Verification can be performed by, for example, a method similar to a digital signature verification method used for a semi-fragile digital watermark or the like. As shown in FIG. 5B, the image whose signature is to be verified is subjected to orthogonal transformation such as DCT or wavelet transformation, and the image is transformed into DCT coefficients or wavelet coefficients. From the obtained coefficients, a plurality of pairs, the same as when the signature was generated, are selected, and for each pair, the signature is verified using the following conditions (C1) to (C3). If any of the following conditions (C1) to (C3) is satisfied, it can be determined that “falsification has not occurred”; otherwise, it can be determined that “falsification has occurred”.
Condition (C1): p ′ _i -Q ' _i > M and Sig _i = 0
Condition (C2): | p ' _i -Q ' _i | ≦ M (Sig _i Regardless of the value of
Condition (C3): p ′ _i -Q ' _i <-M and Sig _i = 1
Where p ' _i And q ' _i Is the signature bit Sig on the signature verification side (generally, lossy compression). _i Are the wavelet coefficients used to generate, and as shown in FIG. _i And q ' _i Is the same vector ν as that on the signature generation side. _i Is determined by M is a margin value for avoiding false alarms caused by lossy compression.
[0027]
As can be seen from the above equation (1a) and condition (C1), p on the signature generation side _i -Q _i ≧ 0, and p ′ on the signature verification side _i -Q ' _i If ≦ M (the magnitude relationship is reversed), it is determined that “falsification has occurred”. As can be seen from the above equation (1b) and the conditions (C2) and (C3), p _i -Q _i <0, and the signature verification side p ′ _i -Q ' _i If> M (the magnitude relationship is reversed), it is determined that “falsification has occurred”. As described above, the reason for giving a certain margin to the falsification determination using the margin value M is that slight deterioration of the image due to irreversible compression or the like is allowed (it is not determined that falsification has occurred), and malicious processing is performed. This is because only a significant change such as an attack is not permitted (it is determined that there is tampering). Note that the signature generation method and the signature verification method are not limited to the examples described above, and other methods may be employed.
[0028]
[Effects of First Embodiment]
As described above, in the first embodiment, the configuration 100a on the signature generation side generates digital signature data and image correction information, and saves them in the storage unit without embedding them in the image data. Further, in the first embodiment, the signature verification-side configuration 100b corrects the image data based on the image correction information, and then generates the signature verification-side electronic signature data. The signature is verified by comparing with. According to the data processing method according to the first embodiment that performs such processing, the digital signature data on the signature generation side is managed without being embedded in the image data, and the digital signature data and the image correction information on the signature generation side are signed. Since the data is passed to the configuration on the verification side, tampering can be verified with high accuracy even if the image data to be verified has been subjected to enlargement / reduction processing (scaling).
[0029]
<< 2nd Embodiment >>
[Configuration of signature generation side]
FIG. 6 is a block diagram illustrating a configuration (data processing device) 200a on the signature generation side that performs the data processing method according to the second embodiment of the present invention. 6, the same reference numerals are given to the same or corresponding components as those in FIG. 1 (first embodiment).
[0030]
As shown in FIG. 6, the configuration 200a on the signature generation side includes a signature unit 101, an electronic signature management unit 102 on the signature generation side, a storage unit 103 on the signature generation side, and an image ID issuing unit (data ID issuing unit). ) 104 and an ID embedding unit (ID adding unit) 105. The image ID issuing unit 104 generates an image ID for an image input from the input terminal 10. The ID embedding unit 105 embeds the image ID obtained from the image ID issuing unit 104 in the image data obtained from the input terminal 10, and outputs the image data after the image ID is embedded from the output terminal 50. The signature unit 101 has a configuration similar to that of the first embodiment, and calculates and outputs digital signature data and image correction information for image data in which an image ID is embedded. The electronic signature management unit 102 converts the information in which the image ID issued by the image ID issuing unit 104, the electronic signature data output from the signature unit 101, and the image correction information output from the signature unit 101 are associated with each other into an electronic signature. The information is stored in the storage unit 103 as the management table 103b.
[0031]
The configuration 200a on the signature generation side is, for example, a computer system. The signature unit 101, the electronic signature management unit 102, the image ID issuing unit 104, and the ID embedding unit 105 are, for example, computing devices of a computer system. The storage unit 103 is, for example, a semiconductor memory or a hard disk device of a computer system. However, the storage unit 103 itself is a storage device arranged at a different position from the signature unit 101, the electronic signature management unit 102, the image ID issuing unit 104, and the ID embedding unit 105, for example, a storage device of a server on a network. It can also be. The information of the electronic signature management table 103a stored in the storage unit 103 is transferred to a signature verification-side configuration 200b described below via, for example, a network.
[0032]
[Configuration of signature verification side]
FIG. 7 is a block diagram illustrating a configuration (data processing device) 200b on the signature verification side that performs the data processing method according to the second embodiment of the present invention. 7, the same reference numerals are given to the same or corresponding components as those in FIG. 2 (first embodiment).
[0033]
As shown in FIG. 7, the signature verification-side configuration 200b includes a verification unit 120, a signature verification-side electronic signature management unit 121, an ID detection unit 122, and an electronic device passed from the signature generation-side configuration 200a. And a storage unit 123 on the signature verification side for storing the signature management table 103a. The ID detection unit 122 extracts an image ID from image data to be verified (data to be verified) from the input terminal 21 and outputs the image ID. The verification unit 120 has a configuration similar to that of the first embodiment, and verifies the image data to be verified input from the input terminal 21 using the electronic signature data and the image correction information. , And outputs the verification result from the output terminal 23. The electronic signature management unit 121 extracts the electronic signature data and the image correction information of the image specified by the image ID from the electronic signature management table 103b of the storage unit 123 using the image ID detected by the ID detection unit 122, and performs verification. Output to the means 120.
[0034]
The configuration 200b on the signature verification side is, for example, a computer system. The verification unit 120, the electronic signature management unit 121, and the ID detection unit 122 are, for example, computing devices of a computer system. The storage unit 123 is, for example, a semiconductor memory or a hard disk device of a computer system. However, the storage unit 123 itself on the signature verification side is a storage device arranged at a different position from the verification unit 120, the electronic signature management unit 121, and the ID detection unit 122, for example, a storage device of a server on a network. You can also. Further, the storage unit 123 on the signature verification side and the storage unit 103 on the signature generation side can be the same storage device.
[0035]
[Operation of signature generation side]
As shown in FIG. 6, the image ID issuing unit 104 generates a unique (unique) image ID for identifying an image, and outputs it to the ID embedding unit 105 and the electronic signature management unit 102. The image ID may be any content that can specify the image, and can be generated from a random value, the content of the content, a time stamp, and the like. Further, the image ID issuing unit 104 may generate information other than the image ID, for example, a comment or time information on the image in association with the image ID. In this case, a comment, time information, or the like may be stored in the electronic signature management table 103b, or may be embedded in the image as a digital watermark message by the ID embedding unit 105.
[0036]
The ID embedding unit 105 embeds the image ID obtained from the image ID issuing unit 104 in the image data obtained from the input terminal 10, and outputs the image data after the ID embedding to the image output terminal 50. The image data with the ID embedded is output to the signature unit 101. The ID embedding unit 105 uses, for example, a robust digital watermark used for copyright protection. As the robust digital watermark, for example, a method including the following steps can be used, but the method is not particularly limited.
(Step ST11): The image ID data and the message data to be embedded are encoded using an error correction code such as a BCH code or a turbo code.
(Step ST12): The coefficient after frequency transformation by wavelet transformation or DCT is quantized with a slightly larger quantization coefficient, and data after error correction encoding is repeatedly embedded in the LSB bit plane of the quantized coefficient.
[0037]
However, the image ID does not necessarily need to be embedded in the image data as a digital watermark, and the image ID may be recorded in a comment area or the like of the header of the image file. The operations of the signature unit 101 and the electronic signature management unit 102 are the same as those in the first embodiment.
[0038]
[Operation of the signature verification side]
As shown in FIG. 7, image data of a target image whose signature is to be verified is input to an input terminal 21. As shown in FIG. 7, the ID detection unit 122 detects an image ID from the image data input from the input terminal 21. When the image ID is embedded in the image data as a robust digital watermark, this is detected using a robust digital watermark detection method. Although the detection algorithm in this case is not particularly limited, for example, a method including the following steps can be used.
(Step ST21): Rotation and resolution conversion are performed on the image, and the following steps ST22 to ST25 are performed on an image having a plurality of resolutions and a plurality of angles.
(Step ST22): The coefficients after frequency transformation by wavelet transformation or DCT are quantized by the quantization coefficients used by the ID embedding means 105, and a plurality of data are extracted from the LSB bit plane of the quantized coefficients.
(Step ST23): A mode value is obtained for each of the plurality of extracted data in bit units.
(Step ST24): The data composed of the most frequent value is decoded with the error correction code, and the original image ID and the message are output.
(Step ST25): The processing of steps ST22 to ST24 is performed a plurality of times, and the image ID in the case of the least error is set as the output value.
However, when the image ID is recorded in a comment area or the like of the header of the image file without using the electronic watermark, the image ID is acquired from the header of the image file.
[0039]
The image ID obtained by the ID detection unit 122 is output to the electronic signature management unit 121. The operations of the verification unit 101 and the digital signature management unit 102 are the same as those in the first embodiment.
[0040]
[Effect of Second Embodiment]
As described above, in the second embodiment, the configuration 200a on the signature generation side generates digital signature data and image correction information, and saves them in the storage unit without embedding them in the image data. In the second embodiment, the configuration 200a on the signature generation side adds the image ID to the image data (in some cases, the image ID may be embedded, or in some cases, simply). Further, in the second embodiment, the signature verification side configuration 200b acquires the image ID from the image data, corrects the image data based on the image correction information corresponding to the acquired image ID, and then executes the signature verification side operation. The signature verification is performed by generating digital signature data and comparing the generated digital signature data with the digital signature data on the signature generation side. According to the data processing method according to the second embodiment for performing such processing, the electronic signature data is managed without being embedded in the image data, and the electronic signature data and the image correction information on the signature generation side are configured on the signature verification side. Therefore, even if the image data to be verified has been subjected to enlargement / reduction processing (scaling), tampering can be verified with high accuracy.
[0041]
Further, when image data and image ID are combined by a robust digital watermark in the second embodiment, the association between the image ID and the image data becomes easy, and the image ID and the image A situation in which the link with the data is broken hardly occurs.
[0042]
Further, in the second embodiment, since the image data and the image ID are combined, it is possible to automatically obtain the electronic signature data and the image correction information, and it is possible to automate the falsification detection of the image. .
[0043]
<< 3rd Embodiment >>
[Configuration of signature generation side]
FIG. 8 is a block diagram illustrating a configuration (data processing device) 300a on the signature generation side that performs the data processing method according to the third embodiment of the present invention. In FIG. 8, the same or corresponding components as those in FIG. 6 (second embodiment) are denoted by the same reference numerals.
[0044]
As shown in FIG. 8, the configuration 300a on the signature generation side has a digital signature generation unit 111 instead of the signature unit 101 (FIG. 6). Configuration 200a. Also, as shown in FIG. 8, the configuration 300a on the signature generation side is different from the configuration on the signature generation side shown in FIG. 6 (second embodiment) in that the image correction information is not stored in the electronic signature management table 103c. 200a. Except for these points, the configuration 300a on the signature generation side of the third embodiment is the same as the configuration 200a on the signature generation side of the second embodiment.
[0045]
[Configuration of signature verification side]
FIG. 9 is a block diagram illustrating a configuration (data processing device) 300b on the signature verification side that performs the data processing method according to the third embodiment of the present invention. In FIG. 9, the same or corresponding components as those in FIG. 7 (second embodiment) are denoted by the same reference numerals.
[0046]
As shown in FIG. 9, the configuration 300b on the signature verification side of the third embodiment is different from the signature verification side in that the ID detection unit 122 calculates the image correction information and outputs the image correction information to the verification unit 120. The point that the management table 103c does not include image correction information and the content of data processing for signature verification by the verification unit 120 are different from the signature verification side configuration 200b shown in FIG. 7 (second embodiment). . Except for these points, the configuration 300b on the signature verification side of the third embodiment is the same as the configuration 200b on the signature verification side of the second embodiment.
[0047]
[Operation of signature generation side]
As shown in FIG. 8, the image ID issuing unit 104 generates a unique (unique) image ID for identifying an image, and outputs it to the ID embedding unit 105 and the electronic signature management unit 102. The ID embedding unit 105 embeds the image ID obtained from the image ID issuing unit 104 in the image data obtained from the input terminal 10, and outputs the image data after the ID embedding to the image output terminal 50. The operations of the image ID issuing unit 104, the ID embedding unit 105, and the electronic signature management unit 102 are the same as the operations in the second embodiment.
[0048]
The electronic signature generation unit 111 generates electronic signature data for the image data obtained from the ID embedding unit 105 in the same manner as in the first embodiment (electronic signature generation unit 111 in FIG. 2), and manages the electronic signature. Output to means 102. As shown in FIG. 8, the electronic signature management unit 102 stores an electronic signature management table 103c including an image ID and electronic signature data in the storage unit 103.
[0049]
[Operation of the signature verification side]
As shown in FIG. 9, the ID detection unit 122 detects an image ID from image data input from the input terminal 21. Since the image ID is embedded in the image data as a robust digital watermark, it is detected using a robust digital watermark detection method. Although the detection algorithm in this case is not particularly limited, for example, a method including the following steps can be used.
(Step ST31): Rotation and resolution conversion are performed on an image, and the following steps ST32 to ST35 are performed on an image having a plurality of resolutions and a plurality of angles.
(Step ST32): The coefficients after frequency conversion by wavelet transform, DCT or the like are quantized by the quantization coefficients used by the ID embedding means 105, and a plurality of data are extracted from the LSB bit plane of the quantized coefficients.
(Step ST33): With respect to the plurality of extracted data, a mode value is obtained in bit units.
(Step ST34): The data composed of the most frequent value is decoded by the error correction code, and the original image ID and the message are output.
(Step ST35): The processes of steps ST32 to ST34 are performed a plurality of times, and the image ID in the case of the least error is set as the output value.
[0050]
The image ID thus obtained is output to the electronic signature management unit 121, and the resolution / rotation angle at the time of detecting the image ID is output to the verification unit 120 as image correction information. The verification unit 120 obtains the image correction information from the ID detection unit 122 instead of obtaining the image correction information from the electronic signature management unit 121 as in the case of the second embodiment. The verification unit 120 corrects the image using the image correction information output from the ID detection unit 122, and then performs signature verification. The signature verification method is the same as in the second embodiment.
[0051]
[Effects of Third Embodiment]
As described above, in the third embodiment, the configuration 300a on the signature generation side generates digital signature data and stores them in the storage unit without embedding them in image data. In the third embodiment, the configuration 300a on the signature generation side embeds the image ID in the image data as a digital watermark. Further, in the third embodiment, the configuration 300b on the signature verification side acquires the image ID from the image data, and acquires the image correction information from the information when the image ID was acquired. According to the data processing method according to the third embodiment for performing such processing, the electronic signature data is managed without being embedded in the image data, the electronic signature data on the signature generation side is passed to the configuration on the signature verification side, and Since the correction information is obtained through the image ID detection processing, even if the image data to be verified has been subjected to the enlargement / reduction processing (scaling), the tampering can be verified with high accuracy.
[0052]
Further, according to the third embodiment, since the image correction information is obtained from the rotation information / resolution information obtained at the time of robust digital watermark detection, it is not necessary for the electronic signature management table to manage the image correction information. .
[0053]
<< 4th Embodiment >>
[Configuration of signature generation side]
FIG. 10 is a block diagram illustrating a configuration (data processing device) 400a on the signature generation side that performs the data processing method according to the fourth embodiment of the present invention. In FIG. 10, the same reference numerals are given to the same or corresponding components as those in FIG. 8 (third embodiment).
[0054]
As shown in FIG. 10, the configuration 400a on the signature generation side includes a correction information generation unit 110 that generates image correction information for image data input from the input terminal 10, and an image output from the correction information generation unit 110. An ID embedding unit 105 for embedding the correction information in the image together with the image ID is provided. In other respects, the configuration 400a on the signature generation side of the fourth embodiment is the same as the configuration 300a on the signature generation side of the third embodiment.
[0055]
[Configuration of signature verification side]
FIG. 11 is a block diagram illustrating a configuration (data processing device) 400b on the signature verification side that performs the data processing method according to the fourth embodiment of the present invention. 11, the same reference numerals are given to the same or corresponding components as those in FIG. 9 (third embodiment).
[0056]
As shown in FIG. 11, the configuration 400b on the signature verification side outputs image correction information embedded together with the image ID from the ID detection unit 122 and inputs the information to the verification unit 120. Except for this point, the configuration 400b on the signature verification side of the fourth embodiment is the same as the configuration 300b on the signature verification side of the third embodiment.
[0057]
[Operation of signature generation side]
As shown in FIG. 10, the image ID issuing unit 104 generates a unique (unique) image ID for identifying an image, and outputs it to the ID embedding unit 105 and the electronic signature management unit 102. The correction information generation unit 110 generates and outputs image correction information for the image data input from the input terminal 10. The ID embedding unit 105 adds, to the image data input from the input terminal 10, the image ID obtained from the image ID issuing unit 104 and the image correction information obtained from the correction information generation unit 110, the digital watermark described in the above embodiment. Embed by Except for the above points, the operation of the configuration 400a on the signature generation side of the fourth embodiment is the same as the operation of the configuration 300a on the signature generation side of the third embodiment.
[0058]
[Operation of the signature verification side]
As shown in FIG. 11, the ID detecting means 122 detects the embedded image ID and image correction information from the image data detected from the input terminal 21. The image ID thus obtained is output to the electronic signature management unit 121, and the image ID and the image correction information are detected and output to the verification unit 120. The verification unit 120 corrects the image using the image correction information output from the ID detection unit 122, and then performs signature verification. The method of signature verification is the same as in the second or third embodiment.
[0059]
[Effect of Fourth Embodiment]
As described above, in the fourth embodiment, the configuration 400a on the signature generation side generates digital signature data and stores them in the storage unit without embedding them in the image data. Further, in the fourth embodiment, the configuration 400a on the signature generation side adds the image ID and the image correction information to the image data (in some cases, it may be embedded, or simply may be added). Furthermore, in the fourth embodiment, the configuration 400b on the signature verification side acquires an image ID and image correction information from image data. According to the data processing method according to the fourth embodiment for performing such processing, the electronic signature data is managed without being embedded in the image data, the electronic signature data is passed to the configuration on the signature verification side, and the image correction information is Since the image data is obtained through the ID detection processing, tampering can be verified with high accuracy even if the image data to be verified has been subjected to enlargement / reduction processing (scaling).
[0060]
Further, as in the third embodiment, it is not necessary for the ID detection unit 122 to extract rotation information and resolution information from a robust digital watermark. Therefore, in the fourth embodiment, a general-purpose robust digital watermark component can be used to acquire the image correction information (that is, it is not necessary to customize the robust digital watermark component). Further, in the fourth embodiment, the digital signature management unit 121 and the digital signature management table 103d do not need to manage the image correction information.
[0061]
<< 5th Embodiment >>
[Configuration of signature generation side]
FIG. 12 is an explanatory diagram showing the operation of the electronic signature generation means of the configuration (data processing device) on the signature generation side that performs the data processing method according to the fifth embodiment of the present invention. The configuration on the signature generation side in the fifth embodiment has the same configuration as any of the configurations on the signature generation side in the first to fourth embodiments. The fifth embodiment differs from the first to fourth embodiments in the content of data processing by the electronic signature generation unit 111.
[0062]
As shown in FIG. 12, the electronic signature generation unit 111 of the fifth embodiment not only generates electronic signature data from the input original image data but also down-samples the input original image data. Then, one or more image data whose resolution has been changed differently from the original image is generated, and digital signature data is also generated for the image whose resolution has been changed. Therefore, as shown in the lower part of FIG. 12, the signature data of the electronic signature management tables 103a to 103d is a combination of resolution information and electronic signature data (for example, (1) image size + electronic signature 1, (2)). Resolution information 1 + digital signature 2, (3) resolution information 2 + digital signature 3, etc.).
[0063]
[Configuration of signature verification side]
FIG. 13 is an explanatory diagram showing the operation of the signature verification means of the configuration (data processing device) on the signature verification side that performs the data processing method according to the fifth embodiment of the present invention. The configuration on the signature verification side in the fifth embodiment has the same configuration as any of the configurations on the signature verification side in the first to fourth embodiments. The fifth embodiment differs from the first to fourth embodiments in the content of data processing by the signature verification unit 131.
[0064]
As shown in FIG. 13, the signature verification unit 131 of the fifth embodiment determines that the resolution of the input image data to be verified is the same as the resolution stored as the electronic signature data in the electronic signature management tables 103a to 103d. If different, the image data to be verified is down-sampled to match one of the resolutions stored as digital signature data in the digital signature management tables 103a to 103d. After that, the digital signature data is verified.
[0065]
[Operation of signature generation side]
As shown in FIG. 12, the electronic signature generation unit down-samples the input image data to generate images of a plurality of resolutions. The method of downsampling may use a normal downsampling filter, and is not limited to a specific one. An electronic signature is generated for each resolution image. The same method as that of the first embodiment can be used as a method for generating an electronic signature.
[0066]
The digital signature data of each resolution is multiplexed or associated with the resolution information and output. As the resolution information, in addition to dpi information (the number of dots per unit length) and the like, the ratio of the size of the original image to the image after the resolution change, the image size after downsampling, and the like can be used. Except for this point, the configuration on the signature generation side of the fifth embodiment is the same as the configuration 100a, 200a, 300a, 400a on the signature generation side of the first to fourth embodiments.
[0067]
[Operation of the signature verification side]
As shown in FIG. 13, the signature verification unit selects an electronic signature to be used using the image size of the input image. The selection method uses, for example, an electronic signature generated at the highest resolution among one or a plurality of electronic signatures generated at a resolution smaller than the input image.
[0068]
For example, as shown in FIG. 13, there are three sets of digital signatures, “digital signature 1”, “digital signature 2”, and “digital signature 3”. Of the digital signatures generated at a resolution smaller than the input image, When the digital signature generated at the highest resolution is “digital signature 2”, digital signature 2 is used. At the time of signature verification, the verification of the digital signature for resampling the input image and enlarging / reducing the size of the image in which the digital signature to be used is generated is, for example, the same method as the method described in the first embodiment. Can be used. Except for this point, the configuration on the signature verification side of the fifth embodiment is the same as the signature verification side configurations 100b, 200b, 300b, and 400b of the first to fourth embodiments.
[0069]
[Effects of Fifth Embodiment]
In the case of a semi-fragile electronic signature, when an image having a resolution (small size) lower than the resolution at which the signature was generated is to be verified, it is necessary to up-sample the image to be verified. However, at this time, since the image to be verified contains only the information amount equal to or less than the resolution held at the time of generation of the digital signature, the image is erroneously detected. That occurs). Also, if an electronic signature is generated using the lowest possible resolution, tampering can be detected only at that resolution level, and even if detailed information present in an image with a higher resolution than that is tampered with, It cannot be detected as "tampering", and the detection accuracy deteriorates. According to the fifth embodiment, by retaining the digital signature in each resolution expression, when the size of the image is changed, the most appropriate digital signature is used, thereby reducing erroneous detection. In addition, the falsification detection rate can be increased, and the detection accuracy can be greatly improved as a whole.
[0070]
[Modification of Fifth Embodiment]
In the fifth embodiment, the resolution conversion can be performed simultaneously with the wavelet conversion, as shown in FIGS. If the digital signature data is generated from the sequentially generated LL components (low-frequency components) during the generation of the digital signature and the wavelet transform at the time of image compression, the cost of the filtering process and the like can be reduced. Further, if a wavelet transform compatible with JPEG2000, which is standardized as a next-generation compressed image format, is used, the resistance to JPEG2000 compression is improved.
≪Other applications≫
[0071]
In each of the embodiments described above, a case has been described in which the data for signature generation and the data for verification are image data. However, the present invention can be applied to other data such as audio data.
[0072]
In each of the above-described embodiments, the ID embedding unit and the ID detecting unit may use any method as long as it is a general robust digital watermark. Similarly, the signature generation means and the verification means may be of any type as long as they are generally semi-fragile electronic signatures.
[0073]
Further, in each of the embodiments described above, the case where the image correction information is information such as the size of the image has been described. However, any data may be used as long as the data can restore the scale of the original image.
[0074]
Furthermore, in each of the above-described embodiments, the electronic signature management means and the signature management table need not particularly limit the recording medium or configuration, and may be anything as long as the association between the image ID and the electronic signature data can be maintained. Good. For example, a storage device such as an HDD, a file system, a network service, a wireless service, a removable medium, and the like can be used.
[0075]
Further, in each of the above-described embodiments, the case where the image is scaled at the time of signature verification has been described, but the scaling is not always necessary. For example, scaling is not required for images that have not been resized at all.
[0076]
Furthermore, in each of the embodiments described above, it is described that the image is scaled at the time of signature verification, but it is not particularly necessary to scale the image collectively. Instead of an image, a coefficient after DCT or a coefficient after wavelet transform used inside the digital signature verification may be sequentially scaled and processed.
[0077]
Furthermore, in the second to fifth embodiments, the image ID issuing means is included as the signature generation side, but the image ID issuing means does not need to be in the signature generator, and the image ID is issued from outside. May be given.
[0078]
Further, in each of the above-described embodiments, each means does not need to be in the same device, and data transmission between each means is performed by an internal bus or external bus of a PC, a network or wireless transmission, or storage and transmission by a storage device. There is no particular limitation on transportation by a removable medium or the like.
[0079]
Further, when the configuration of the signature generation side is a computer system, the operation of the signature generation side can be executed according to an application program installed in the computer system. As a method of installing the application program, there are methods such as installation from a storage medium on which the installation program is recorded and download via the Internet. Similarly, when the configuration of the signature verification side is a computer system, the operation of the signature generation side can be executed according to an application program installed in the computer system. As a method of installing the application program, there are methods such as installation from a storage medium on which the installation program is recorded and download via the Internet.
[0080]
【The invention's effect】
As described above, according to the present invention, the configuration on the signature generation side manages the electronic signature data, the configuration on the signature verification side obtains the image ID and the image correction information, and obtains the image based on the image correction information. The verification is performed after correcting the data back to the original image. For this reason, corrections such as image enlargement / reduction performed in the configuration on the signature generation side are not regarded as tampering, so that even if the image is scaled, the tampering can be verified with high accuracy. is there.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration (data processing device) on a signature generation side that executes a data processing method according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a signature unit of FIGS. 1 and 6;
FIG. 3 is a block diagram illustrating a configuration (data processing device) on the signature verification side that executes the data processing method according to the first embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a verification unit in FIGS. 3, 7, 9, and 11;
FIGS. 5A and 5B are explanatory diagrams respectively showing a signature generation process and a signature verification process according to the first to fifth embodiments of the present invention.
FIG. 6 is a block diagram illustrating a configuration (data processing device) on a signature generation side that performs a data processing method according to a second embodiment of the present invention.
FIG. 7 is a block diagram illustrating a configuration (data processing device) on a signature verification side that performs a data processing method according to a second embodiment of the present invention.
FIG. 8 is a block diagram illustrating a configuration (data processing device) on a signature generation side that performs a data processing method according to a third embodiment of the present invention.
FIG. 9 is a block diagram showing a configuration (data processing device) on the signature verification side that executes a data processing method according to a third embodiment of the present invention.
FIG. 10 is a block diagram illustrating a configuration (data processing device) on a signature generation side that performs a data processing method according to a fourth embodiment of the present invention.
FIG. 11 is a block diagram illustrating a configuration (data processing device) on a signature verification side that performs a data processing method according to a fourth embodiment of the present invention.
FIG. 12 is an explanatory diagram illustrating an operation of a digital signature generation unit according to a fifth embodiment of the present invention.
FIG. 13 is an explanatory diagram illustrating an operation of a digital signature verification unit according to a fifth embodiment of the present invention.
FIG. 14 is an explanatory diagram showing an operation of a digital signature generation unit according to a modification of the fifth embodiment of the present invention.
FIG. 15 is an explanatory diagram illustrating an operation of a digital signature verification unit according to a modification of the fifth embodiment of the present invention.
FIG. 16 is an explanatory diagram showing a conventional fragile digital watermark embedding operation.
FIG. 17 is an explanatory diagram showing a conventional fragile digital watermark verification operation.
[Explanation of symbols]
100a, 200a, 300a, 400a Configuration of signature generation side (data processing device)
100b, 200b, 300b, 400b Configuration of signature verification side (data processing device)
101 signature means,
102 electronic signature management means on the signature generation side,
103 signature generating side storage means,
103a, ..., 103d electronic signature management table,
104 image ID issuing means (data ID issuing means),
105 ID embedding means (ID adding means),
110 correction information generating means,
111 electronic signature generating means,
120 verification means,
121 electronic signature management means on the signature verification side,
122 ID detecting means,
123 signature verification side storage means,
130 image correction means (data correction means);
131 signature verification means.

Claims (22)

A data processing method performed on input data by a configuration of a signature generation side,
Receiving the input data and a data ID identifying the input data,
Generating digital signature data on the signature generation side based on the input data;
Generating data correction information based on the correction content applied to the input data;
Storing a digital ID management table including at least one of a combination of a data ID for specifying the input data, the digital signature data on the signature generation side, and the data correction information. Method. A data processing method executed on data to be verified by a configuration of a signature verifying side,
A step in which the configuration of the signature verification side receives the data to be verified and a data ID for specifying the data to be verified;
Acquiring data correction information corresponding to a data ID specifying the data to be verified and electronic signature data on the signature generation side from the electronic signature management table according to claim 1;
Correcting the verification target data using the obtained data correction information,
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. Determining whether data has been tampered with. A data processing method performed on input data by a configuration of a signature generation side,
Receiving the input data by the signature generation-side configuration;
Adding a data ID identifying the input data to the input data;
Generating digital signature data on the signature generation side based on the input data;
Generating data correction information based on the correction content applied to the input data;
Storing a digital ID management table including at least one of a combination of a data ID for specifying the input data, the digital signature data on the signature generation side, and the data correction information. Method. A data processing method executed on data to be verified including a data ID by a configuration of a signature verifying side,
The configuration of the signature verification side receives the data to be verified,
Extracting a data ID included in the verification target data;
Acquiring the data correction information corresponding to the extracted data ID and the electronic signature data of the signature generation side from the electronic signature management table according to claim 3;
Correcting the verification target data using the obtained data correction information,
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. Determining whether data has been tampered with. A data processing method performed on input data by a configuration of a signature generation side,
Receiving the input data by the signature generation-side configuration;
Embedding a data ID identifying the input data in the input data as a digital watermark;
Generating digital signature data on the signature generation side based on the input data;
Storing an electronic signature management table including at least one combination of a data ID specifying the input data and the electronic signature data of the signature generation side. A data processing method executed on data to be verified in which a data ID is embedded as a digital watermark by a configuration of a signature verification side,
The configuration of the signature verification side receives the data to be verified,
Detecting a data ID embedded as an electronic watermark in the verification target data, and detecting data correction information related to the verification target data;
Acquiring the electronic signature data of the signature generation side corresponding to the detected data ID from the electronic signature management table according to claim 5;
Correcting the verification target data using the detected data correction information,
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. Determining whether data has been tampered with. A data processing method performed on input data by a configuration of a signature generation side,
Receiving the input data by the signature generation-side configuration;
Generating data correction information based on the correction content applied to the input data;
Adding a data ID specifying the input data and the data correction information to the input data;
Generating digital signature data on the signature generation side based on the input data;
Storing an electronic signature management table including at least one combination of a data ID specifying the input data and the electronic signature data of the signature generation side. A data processing method executed on data to be verified including a data ID and data correction information by a configuration of a signature verification side,
The configuration of the signature verification side receives the data to be verified,
Detecting a data ID and data correction information included in the verification target data;
Correcting the verification target data based on the detected data correction information,
Acquiring the electronic signature data of the signature generation side corresponding to the detected data ID from the electronic signature management table according to claim 7;
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. Determining whether data has been tampered with. 8. The method according to claim 1, wherein in the step of generating the digital signature data on the signature generation side, the resolution of the input data is changed to generate digital signature data for the changed input data. The data processing method according to any one of the above. 10. The data processing method according to claim 9, wherein the generation of the digital signature data after the resolution change is a generation of digital signature data for a reduced image obtained in the process of the wavelet transform processing of the input data. 11. The method according to claim 9, wherein in the step of obtaining the digital signature data on the signature generation side corresponding to the detected data ID from the electronic signature management table, after changing the resolution from the electronic signature management table according to claim 9 or 10. 9. The data processing method according to claim 2, wherein electronic signature data for the input data is acquired. A data processing device that receives input data and a data ID that specifies the input data, and executes data processing on the signature generation side,
Electronic signature generation means for generating digital signature data on the signature generation side based on the input data;
Correction information generating means for generating data correction information based on the correction content applied to the input data,
An electronic signature management unit on the signature generation side that stores in a storage unit an electronic signature management table including at least one combination of a data ID for specifying the input data, the electronic signature data on the signature generation side, and the data correction information. A data processing device comprising: A data processing device that receives data to be verified and a data ID that specifies the data to be verified, and executes data processing on the signature verification side,
An electronic signature management unit on the signature verification side for obtaining data correction information corresponding to a data ID for specifying the data to be verified and the electronic signature data on the signature generation side from the electronic signature management table according to claim 12.
Data correction means for correcting the data to be verified using the obtained data correction information,
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. What is claimed is: 1. A data processing apparatus comprising: signature verification means for determining whether data has been tampered with. A data processing device that receives input data and performs data processing on a signature generation side,
Data ID issuing means for issuing a data ID specifying the input data;
ID adding means for adding the data ID to the input data;
Electronic signature generation means for generating digital signature data on the signature generation side based on the input data;
Correction information generating means for generating data correction information based on the correction content applied to the input data,
An electronic signature management unit on the signature generation side that stores in a storage unit an electronic signature management table including at least one combination of a data ID for specifying the input data, the electronic signature data on the signature generation side, and the data correction information. A data processing device comprising: A data processing device that receives data to be verified including a data ID and performs data processing on a signature verification side,
ID detecting means for extracting a data ID included in the data to be verified,
An electronic signature management unit on the signature verification side for obtaining data correction information corresponding to the extracted data ID and the electronic signature data on the signature generation side from the electronic signature management table according to claim 14,
Data correction means for correcting the data to be verified using the obtained data correction information,
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. What is claimed is: 1. A data processing apparatus comprising: signature verification means for determining whether data has been tampered with. A data processing device that receives input data and performs data processing on a signature generation side,
ID embedding means for embedding a data ID for specifying the input data in the input data as a digital watermark,
Electronic signature generation means for generating digital signature data on the signature generation side based on the input data;
A signature generation-side electronic signature management unit that stores, in a storage unit, an electronic signature management table including at least one combination of a data ID specifying the input data and the signature generation-side electronic signature data. Data processing device. A data processing device that receives data to be verified in which a data ID is embedded as a digital watermark and executes data processing on the signature verification side,
ID detection means for detecting a data ID embedded as a digital watermark in the data to be verified, and detecting data correction information on the data to be verified,
An electronic signature management unit on the signature verification side for obtaining the electronic signature data on the signature generation side corresponding to the extracted data ID from the electronic signature management table according to claim 16;
Data correction means for correcting the data to be verified using the detected data correction information,
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. What is claimed is: 1. A data processing apparatus comprising: signature verification means for determining whether data has been tampered with. A data processing device that receives input data and performs data processing on a signature generation side,
Correction information generating means for generating data correction information based on the correction content applied to the input data,
Data adding means for adding the data ID and the data correction information to the input data;
Electronic signature generation means for generating digital signature data on the signature generation side based on the input data;
A signature generation-side electronic signature management unit that stores, in a storage unit, an electronic signature management table including at least one combination of a data ID specifying the input data and the signature generation-side electronic signature data. Data processing device. A data processing device that receives data to be verified including a data ID and data correction information and performs data processing on a signature verification side,
Data detection means for detecting the data ID and the data correction information from the verification target data,
Data correction means for correcting the data to be verified using the detected data correction information,
An electronic signature management unit on the signature verification side that acquires the electronic signature data on the signature generation side corresponding to the extracted data ID from the electronic signature management table according to claim 18.
The digital signature data of the signature verification side is generated from the corrected data to be verified, and the digital signature data of the signature generation side is compared with the digital signature data of the signature verification side. What is claimed is: 1. A data processing apparatus comprising: signature verification means for determining whether data has been tampered with. 19. The data according to claim 12, wherein the digital signature generation unit changes the resolution of the input data and generates digital signature data for the changed input data. Processing equipment. 21. The data processing apparatus according to claim 20, wherein the generation of the digital signature data after the resolution change is generation of digital signature data for a reduced image obtained in a process of a wavelet transform process of input data. 22. The electronic signature management means on the signature verification side acquires electronic signature data for input data after resolution change from the electronic signature management table according to claim 20. The data processing device according to any one of 13, 15, 17, and 19.

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